4 LF757NDCDA-DOSY-GPM

Item Number: 0792292
1 1
$16,327.33
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When Will it Ship: Contact for Lead Time
Estimated transit time: 2 to 5 Business Days

Brand - Watts
  • Size: 4 inch
  • Weight: 263.0 lb
  • Lead Free* Construction
  • Domestic OSY Shutoff Valves
  • GPM Metered Bypass
  • 304 (Schedule 40) Stainless Steel Housing
  • Maximum Working Pressure: 175 PSI
  • Installation Orientation: Horizontal, Vertical, or N Pattern
  • Approved to ASSE 1048 and CSA B64.5

Description

The 4 inch Watts LF757NDCDA-DOSY-GPM Lead Free Double Check Detector Backflow Preventer Assembly protects potable water supplies from non-health hazard contaminants. This N pattern assembly is designed for fire protection systems and other cross-connections where backsiphonage or backpressure might occur. Key features include a durable 304 stainless steel housing, domestic OSY shutoff valves, and a GPM metered bypass for detecting leaks and unauthorized water use. Its compact, lightweight design allows for horizontal, vertical, or N pattern installation, offering ease of maintenance with no special tools required. This unit is approved by ASSE 1048, CSA B64.5, UL Classified, and FM Approved, ensuring reliability and compliance.

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Mainline Connections

  • The main assembly features flanged connections for secure installation into your pipeline.
  • It includes domestic OSY (Outside Stem and Yoke) resilient seated gate valves for isolation.
  • Groove fittings are incorporated to allow for integral pipeline adjustment during installation.

Bypass Connections

  • The metered bypass section includes four test cocks for verification and maintenance procedures.
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Additional Details

This 4 inch Lead Free N Pattern Double Check Detector Backflow Preventer Assembly is engineered to prevent the reverse flow of non-potable water and fire protection substances from entering the potable water supply. It is specifically designed for non-health hazard applications where backsiphonage or backpressure could occur.

This assembly is ideal for protecting cross-connections in fire protection systems and other service line entrances where non-toxic contaminants might be present.

Features

  • Lead Free* construction: Wetted surface contacted by consumable water contains less than 0.25% of lead by weight
  • Extremely compact modular design with a single access cover for ease of maintenance
  • Approximately 70% lighter than traditional designs for easier installation
  • Constructed with 304 (Schedule 40) stainless steel housing and sleeve for durability
  • Gallons per minute (GPM) metered bypass for detecting underground leaks and unauthorized water use
  • Groove fittings enable integral pipeline adjustment
  • Unique Tri-link check design provides the lowest pressure loss
  • Ungeared ease of serviceability, requiring no special tools
  • Includes domestic OSY (Outside Stem and Yoke) resilient seated gate valves and captured spring check valves
  • Approved for horizontal, vertical, or N pattern installations
  • Features four test cocks and replaceable check disc rubber

Specifications

  • Size: 4 inch
  • Model: LF757NDCDA-DOSY-GPM
  • Pattern: N Pattern
  • Valve Type: Domestic OSY (Outside Stem and Yoke) Resilient Seated Gate Valves
  • Bypass: Gallons per Minute (GPM) Metered
  • Test Cocks: 4

Materials

  • Housing & Sleeve: 304 (Schedule 40) Stainless Steel
  • Elastomers: EPDM, Silicone, Buna-N
  • Tri-link Checks: Noryl®, Stainless Steel
  • Check Discs: Reversible Silicone or EPDM
  • Test Cocks Body: Lead Free* Bronze
  • Pins & Fasteners: 300 Series Stainless Steel
  • Springs: Stainless Steel

Performance

  • Maximum Working Pressure: 175 PSI (12.1 bar)
  • Temperature Range: 33°F - 140°F (0.5°C - 60°C)

Physical Characteristics

  • Weight: 198 lbs (89 kg)
  • Installation Orientation: Horizontal, Vertical, or N Pattern

Certificates & Approvals

  • Approved by the Foundation for Cross-Connection Control and Hydraulic Research at The University of Southern California (FCCCHR-USC)
  • AWWA C510-97
  • ASSE 1048
  • CSA B64.5
  • UL Classified
  • FM Approved (**BFG & OSY Only)
  • NSF Certified to NSF/ANSI 372

FAQs

What is the primary purpose of the Watts LF757NDCDA-DOSY-GPM assembly?

This 4 inch Lead Free Double Check Detector Backflow Preventer Assembly is designed to prevent the reverse flow of non-potable water and fire protection substances into the potable water supply due to backsiphonage or backpressure. It is intended for non-health hazard applications.

What type of connections does this backflow preventer use?

The main assembly features flanged connections and includes domestic OSY (Outside Stem and Yoke) resilient seated gate valves. Groove fittings are also incorporated for integral pipeline adjustment during installation.

What materials are used in the construction of this backflow preventer?

The housing and sleeve are made from 304 (Schedule 40) Stainless Steel. Elastomers include EPDM, Silicone, and Buna-N, while test cocks feature a Lead Free* Bronze Body.

Can this backflow preventer be installed in any orientation?

Yes, this model is approved for horizontal, vertical, or N pattern installations, offering flexibility to suit various piping configurations.

What is the significance of the GPM metered bypass?

The gallons per minute (GPM) metered bypass is included to help detect underground leaks and unauthorized water usage, providing an additional layer of system monitoring.

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